usb: gadget : fix use-after-free in composite_dev_cleanup()

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget : fix use-after-free in composite_dev_cleanup()

1. In func configfs_composite_bind() -> composite_os_desc_req_prepare():

if kmalloc fails, the pointer cdev->os_desc_req will be freed but not

set to NULL. Then it will return a failure to the upper-level function.

2. in func configfs_composite_bind() -> composite_dev_cleanup():

it will checks whether cdev->os_desc_req is NULL. If it is not NULL, it

will attempt to use it.This will lead to a use-after-free issue.

BUG: KASAN: use-after-free in composite_dev_cleanup+0xf4/0x2c0

Read of size 8 at addr 0000004827837a00 by task init/1

CPU: 10 PID: 1 Comm: init Tainted: G O 5.10.97-oh #1

kasan_report+0x188/0x1cc

__asan_load8+0xb4/0xbc

composite_dev_cleanup+0xf4/0x2c0

configfs_composite_bind+0x210/0x7ac

udc_bind_to_driver+0xb4/0x1ec

usb_gadget_probe_driver+0xec/0x21c

gadget_dev_desc_UDC_store+0x264/0x27c